Concrete mold molding process



Dec. 8, 1953 H. CARLSON CONCRETE MOLD MOLDING PROCESS Filed Sept 18, 1951 INVENTOR. HENRY L. CAELSO/V ATTORNEY Patented Dec. 8, 1953 i UNITED STATES PATENT OFFICE 2,661,518 CONCRETE MOLD MOLDING PROCESS Henry L. Carlson, Kings Park, N. Y.

Application September 18, 1951, Serial N0. 247,097

3 Claims. 1

This invention relates to concrete molds and molding processes suitable for molding truncated cones and other shapes out of Portland cement concrete, and is herein illustrated as embodied in a division of copending patent application Serial No. 91,849, filed May 6, 1949.

As there illustrated, the process produces a truncated cone, with a nearly continuous outer wall made by casting or pouring cement mortar between an outer form which rests with its small end on the ground, where it includes a flat plate, and an inner form set within the outer form and including a flat end plate closing the small end and. resting on the aforesaid flat plate.

The inner form is preferably adapted to be temporarily locked to the outer form to prevent the inner form from floating up when liquid cement concrete is poured in. The forms may be braced apart at the top to ensure centering them properly.

Preferably the forms include aligned round holes adapted to receive a rod or pipe transversely near the center of gravity, so that the ends of the rod may be engaged by crane or derrick cables and the derrick enabled to lift the cast cone and invert it.

Usually, it is preferably, after the concrete is poured and set, to release the lock holding the forms together and lift out the inner form, then invert the outer form, still carrying the cast cone, and then remove the outer form, releasing it by taps of a hammer if it tends to stick.

The truncated cone, suitable for a cess-pool top is usually provided with long oval openings to permit a siphon or other pipe to be readily inserted through any of them.

The oblong or oval openings may be closed by suitable or small shapes of concrete.

When a cess-pool is to be deeply buried the cylindrical cone top may carry a cylindrical upward extension so as to carry a flat top cover at the level of the ground surface.

Other features and advantages will hereinafter appear.

In the accompanying drawings:

Fig. 1 shows the molds in transverse section;

Fig. 2 shows them in plan view;

Fig. 3 shows the finished molded top cone section in place.

The truncated cone top section III was molded in the form shown in Figs. 1 and 2 in which is seen an outer form in the shape of an inverted truncated cone or cone frustum II resting on its flat closed bottom I2, with spreading sides I3, and strengthening outer flange I4 at the top.

In this outer form II is set the inner inverted truncated cone I5 having a flat bottom It adapted to lie on the bottom I2 and to be locked down on the bottom I 4 by wedge pins I'I passing through ears I8 that project upward through the bottom I6.

The inner form I5 is strengthened by an inwardly projecting top flange I9 and is held or steadied by removable spanning elements 20 at the tops of the two forms.

The cone forms are provided with elongated openings 2I adapted to be blocked by cores 22 while the concrete is being poured, and are also provided with elliptical openings 23 for holding a projecting pipe length 24 or other core or rod used for handling the hardened cone.

A 122:4 cement mixture using fine aggregate known as grits or using half inch gravel, is found to yield a structure hardening for handling in less than 24 hours and for lifting by hooks and for withstanding road transportation, the cone described being a little less than 8 feet diameter at the base. It is cast around the pipe 24 so the pipe 24 and pins I! hold the form II against floating up.

When the cement has hardened the pipe 24 and. cores 22 removed, and the form I5 is lifted by derrick hooks caught in the lifting ears 25 and swung out of the way.

Then the pipe 24 is reinserted, the form I I and cement cone are lifted by hooks caught around the pipe, and the cone and outer form I5 inverted and set on the ground.

Then the pipe 24 is removed and the outer form lifted off by the lifting ears 26. If this outer form II tends to stick, as by adhesion or suction, it is easily released by tapping on the outside with a hammer.

The pipe 24 is preferably so located that the cone element turns on it as on its center of gravity.

The elongated openings 2| provide for the insertion of pipes for plumbing, or, if desired, for cess-pools in series so that a second receives any overflow of the first through a pipe set in an opening 2|.

It will be noted that the mold has an inner part and an outer part and the concrete rests partly on the outer part of the mold.

Having thus described in some detail certain embodiments of the invention, what is claimed is:

1. The process of molding a frustum conical cement concrete unit which consists in pouring the cement concrete into a mold formed by two concentric spaced frustum conical forms travrsed by a projecting rod at about the center of gravity of the hardened unit, removing the pipe when the concrete has hardened, removing the inner form, reinserting the pipe, inverting the unit, and removing the outer form.

2. The process of molding a frustum conical cement concrete unit which consists in fastening an inner closed end frustum conical form against a closed end frustum conical outer form pouring the cementconcrete into the mold formed by said formswhile traversed by a projecting rod at about the center of gravity of the hardened unit, re-

moving the pipe when the concrete has hardened.

forming a pair of transversely aligned openings in the molded product near its center of gravity, removing the inner form after the concrete has set, removing the core means, passing a rod through said openings, inverting the molded product together with the outer form by revolving around the rod, and removing the outer form.

HENRY L. CARLSON.

References: Cited in the file of this, patent UNITED STATES PATENTS Number Name Date 1,585,455 Wood May 18, 1926 1 ,g2fh56fl Helmers Sept. 19, 1933 FOREIGN PATENTS Number. Country Date 260:8'89 Great Britain Nov. 11, 1926 

